The takeover of Bengal by the East India Company in 1757. The main actors were Robert Clive, Amir Chand (Omichund), Mir Jafar, Nabakrishna Deb, Alivardi Khan and Siraj-ud-Daulah.

I just wrote a blog post about this, so the history is fresh in my mind.

There was a lot of big-picture political and military action, but the heart of the action was a conspiracy so ludicrous, it sounds like its out of a comedy movie (it involved, for instance, two versions of a treaty: a fake one to double cross one of the conspirators; and a "real" one. Absurd and funny until you realize this actually happened and led to the eventual British colonization of India.

http://en.wikipedia.org/wiki/Bat...

Mir Jafar and the Seths desired that the confederacy between the British and himself be kept secret from Omichund, but when he found out about it, he threatened to betray the conspiracy if his share was not increased to three million rupees (£ 300,000). Hearing of this, Clive suggested an expedient to the Committee. He suggested that two treaties be drawn – the real one on white paper, containing no reference to Omichund and the other on red paper, containing Omichund’s desired stipulation, to deceive him. The Members of the Committee signed on both treaties, but Admiral Watson signed only the real one and his signature had to be counterfeited on the fictitious one. Both treaties and separate articles for donations to the army, navy squadron and committee were signed by Mir Jafar on 4 June.

Lord Clive testified and defended himself thus before the House of Commons of Parliament on 10 May 1773, during the Parliamentary inquiry into his conduct in India:

"Omichund, his confidential servant, as he thought, told his master of an agreement made between the English and Monsieur Duprée [a general of the French East India Company] to attack him, and received for that advice a sum of not less than four lacks of rupees. Finding this to be the man in whom the nabob entirely trusted, it soon became our object to consider him as a most material engine in the intended revolution. We therefore made such an agreement as was necessary for the purpose, and entered into a treaty with him to satisfy his demands. When all things were prepared, and the evening of the event was appointed, Omichund informed Mr. Watts, who was at the court of the nabob, that he insisted upon thirty lacks of rupees, and five per cent. upon all the treasure that should be found; that, unless that was immediately complied with, he would disclose the whole to the nabob; and that Mr. Watts, and the two other English gentlemen then at the court, should be cut off before the morning. Mr. Watts, immediately on this information, dispatched an express to me at the council. I did not hesitate to find out a stratagem to save the lives of these people, and secure success to the intended event. For this purpose we signed another treaty. The one was called the Red, the other the White treaty. This treaty was signed by every one, except admiral Watson; and I should have considered myself sufficiently authorised to put his name to it, by the conversation I had with him. As to the person who signed admiral Watson's name to the treaty, whether he did it in his presence or not, I cannot say; but this I know, that he thought he had sufficient authority for so doing. This treaty was immediately sent to Omichund, who did not suspect the stratagem. The event took place, and success attended it; and the House, I am fully persuaded, will agree with me, that, when the very existence of the Company was at stake, and the lives of these people so precariously situated, and so certain of being destroyed, it was a matter of true policy and of justice to deceive so great a villain."